We're updating a legacy system that used Vanco VAN-280502 HDMI Tx/Rx units for videroconference cameras. (Previously Vaddio or Polycom, now Cisco/Tandberg Precision HD). The Polycom's had worked, but now as soon as the HDMI cable is plugged into the PHD, the camera hums. (This occurs even when the camera isn't powered locally). We swapped in some Extrons in place of the Vanco's which worked fine.
The questions is--is there a pin-out diagram available for the Cat5's from Vanco? I'm waiting to hear back from their engineering dep't for a while now.
My gut tells me that this all has to do with hot plug detect, and possibly a polarity issue(?). I'm curious as to how Vanco powers the Tx unit remotely (on what pins), and if HPD is on another pair.